My friend earned her PhD in Tehran Iran, I assume from the primary university. She received many awards and published several articles in Condensed-Matter/Cosmology. However when she applied to several post-doc positions in the United States, she was denied, not because of her experience, but because her PhD was earned in Iran. I do not understand why this would cause a problem in the United States. She was forced into a situation to either chose to be admitted as a graduate student and earn her PhD again, or simply stay in Iran. She is currently admitted as a graduate student in the US.
Why is getting your PhD in Iran invalid for obtaining a post-doc position in the US?
Is there away around this problem? Can she bounce off from her graduate position?